Numerous techniques exist for mounting an integrated circuit chip to a ceramic substrate. These methods have in common the fact that they are directed to providing a reliable interconnection between conductor runs on the ceramic substrate and contact pads on the integrated circuit chip itself. Under some circumstances, the assembly of the chip and the substrate is mounted in a package, and leads extend from the package for connecting the chip to other components. Typically, the leads may enable the package to be plugged into a mating socket that is mounted on an etched circuit board (ECB). Under other circumstances, it may be desired to mount the substrate directly to an ECB. When the signals that pass between the conductor runs of the ECB and the conductor runs of the substrate are at low frequencies, it is not necessary to pay a great deal of attention to the electrical characteristic of the interconnections between the substrate and the circuit board, but as signal frequency increases the demands that are placed on the interconnections in order to avoid degradation of the signal become more severe. One electrical connector that is able to transmit high frequency signals without undue degradation is described in U.S. Pat. No. 4,255,003 issued Mar. 10, 1981. In the case of that connector, the substrate is fitted in a recess in the circuit board, and the conductor runs on the substrate extend to the periphery of the substrate and align at the periphery with corresponding conductor runs on the upper surface of the board. A frame-like pressure pad of elastomer, having conductive fingers on its lower surface, is fitted so that it bridges the gap between the ceramic substrate and the circuit board, and the conductive fingers establish electrical connection between the conductor runs of the substrate and the corresponding conductor runs of the circuit board. A frame member is fitted over the pressure pad and is secured to the board, compressing the elastomer so that contact force is provided for maintaining the conductive fingers in contact with the conductor runs. This type of connector has been used successfully with signals at frequencies of up to 10 GHz.